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System.map
In Linux, the file is a symbol table used by the kernel. A symbol table is a look-up between symbol names and their addresses in memory. A symbol name may be the name of a variable or the name of a function. The System.map is required when the address of a symbol name, or the symbol name of an address, is needed. It is especially useful for debugging kernel panics and kernel oopses. The kernel does the address-to-name translation itself when CONFIG_KALLSYMS is enabled so that tools like ksymoops are not required. Internals The following is part of a System.map file: c041bc90 b packet_sklist c041bc94 b packet_sklist_lock c041bc94 b packet_socks_nr c041bc98 A __bss_stop c041bc98 A _end c041c000 A pg0 ffffe400 A __kernel_vsyscall ffffe410 A SYSENTER_RETURN ffffe420 A __kernel_sigreturn ffffe440 A __kernel_rt_sigreturn Because addresses may change from one build to the next, a new System.map is generated for each build of the kernel. Symbol types The character between the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
/boot/
In Linux, and other Unix-like operating systems, the directory holds files used in booting the operating system. The usage is standardized in the Filesystem Hierarchy Standard. Contents The contents are mostly Linux kernel files or boot loader files, depending on the boot loader, most commonly (on Linux) LILO or GRUB. Linux * vmlinux – the Linux kernel * initrd.img – a temporary file system, used prior to loading the kernel * System.map – a symbol lookup table LILO LILO creates and uses the following files: * map – a key file, which records where files needed by LILO during boot are stored. Following kernel upgrades, this file must be regenerated by running the "map installer", which is otherwise the system will not boot. * boot.''xxyy'' – these 512-byte files are backups of boot sectors, either the master boot record (MBR) or volume boot record (VBR), created when LILO overwrites a boot sector. ''xx'' and ''yy'' are the major and minor device numbers in hex; for e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux Kernel Oops
In computing, an oops is a serious but non-fatal error in the Linux kernel. An oops often precedes a kernel panic, but may in some cases allow continued operation with compromised reliability. The term does not stand for anything, other than that it is a simple mistake. Functioning When the kernel detects a problem, it kills any offending processes and prints an ''oops message'', which Linux kernel engineers can use in debugging the condition that created the oops and fixing the underlying programming error. After a system has experienced an oops, some internal resources may no longer be operational. Thus, even if the system appears to work correctly, undesirable side effects may have resulted from the active task being killed. A kernel oops often leads to a kernel panic when the system attempts to use resources that have been lost. The official Linux kernel documentation regarding oops messages resides in the file of the kernel sources. Some logger configurations may affect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which includes the kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name "GNU/Linux" to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian, Fedora Linux, and Ubuntu, the latter of which itself consists of many different distributions and modifications, including Lubuntu and Xubuntu. Commercial distributions include Red Hat Enterprise Linux and SUSE Linux Enterprise. Desktop Linux distributions include a windowing system such as X11 or Wayland, and a desktop environment such as GNOME or KDE Plasma. Distributions intended for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symbol Table
In computer science, a symbol table is a data structure used by a language translator such as a compiler or interpreter, where each identifier (or symbols), constants, procedures and functions in a program's source code is associated with information relating to its declaration or appearance in the source. In other words, the entries of a symbol table store the information related to the entry's corresponding symbol. Background A symbol table may only exist in memory during the translation process, or it may be embedded in the output of the translation, such as in an ABI object file for later use. For example, it might be used during an interactive debugging session, or as a resource for formatting a diagnostic report during or after execution of a program. Description The minimum information contained in a symbol table used by a translator and intermediate representation (IR) includes the symbol's name and its location or address. For a compiler targeting a platform with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kernel (operating System)
The kernel is a computer program at the core of a computer's operating system and generally has complete control over everything in the system. It is the portion of the operating system code that is always resident in memory and facilitates interactions between hardware and software components. A full kernel controls all hardware resources (e.g. I/O, memory, cryptography) via device drivers, arbitrates conflicts between processes concerning such resources, and optimizes the utilization of common resources e.g. CPU & cache usage, file systems, and network sockets. On most systems, the kernel is one of the first programs loaded on startup (after the bootloader). It handles the rest of startup as well as memory, peripherals, and input/output (I/O) requests from software, translating them into data-processing instructions for the central processing unit. The critical code of the kernel is usually loaded into a separate area of memory, which is protected from access by application ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kernel Panic
A kernel panic (sometimes abbreviated as KP) is a safety measure taken by an operating system's kernel upon detecting an internal fatal error in which either it is unable to safely recover or continuing to run the system would have a higher risk of major data loss. The term is largely specific to Unix and Unix-like systems. The equivalent on Microsoft Windows operating systems is a stop error, often called a "blue screen of death". The kernel routines that handle panics, known as panic() in AT&T-derived and BSD Unix source code, are generally designed to output an error message to the console, dump an image of kernel memory to disk for post-mortem debugging, and then either wait for the system to be manually rebooted, or initiate an automatic reboot. The information provided is of a highly technical nature and aims to assist a system administrator or software developer in diagnosing the problem. Kernel panics can also be caused by errors originating outside kernel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nm (Unix)
nm (name mangling) is a Unix command used to dump the symbol table and their attributes from a binary executable file (including libraries, compiled object modules, shared-object files, and standalone executables). The output from nm distinguishes between various symbol types. For example, it differentiates between a function that is supplied by an object module and a function that is required by it. nm is used as an aid for debugging, to help resolve problems arising from name conflicts and C++ name mangling, and to validate other parts of the toolchain. This command is shipped with a number of later versions of Unix and similar operating systems including Plan 9. The GNU Project ships an implementation of nm as part of the GNU Binutils package. nm output sample /* * File name: test.c * For C code compile with: * gcc -c test.c * * For C++ code compile with: * g++ -c test.cpp */ int global_var; int global_var_init = 26; static int static_var; static int static_va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix System
Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley (BSD), Microsoft (Xenix), Sun Microsystems (SunOS/ Solaris), HP/ HPE (HP-UX), and IBM (AIX). In the early 1990s, AT&T sold its rights in Unix to Novell, which then sold the UNIX trademark to The Open Group, an industry consortium founded in 1996. The Open Group allows the use of the mark for certified operating systems that comply with the Single UNIX Specification (SUS). Unix systems are characterized by a modular design that is sometimes called the "Unix philosophy". According to this philosophy, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux Kernel
The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU operating system, which was written to be a free (libre) replacement for Unix. Linux is provided under the GNU General Public License version 2 only, but it contains files under other compatible licenses. Since the late 1990s, it has been included as part of a large number of operating system distributions, many of which are commonly also called Linux. Linux is deployed on a wide variety of computing systems, such as embedded devices, mobile devices (including its use in the Android operating system), personal computers, servers, mainframes, and supercomputers. It can be tailored for specific architectures and for several usage scenarios using a family of simple commands (that is, without the need of manually editing its source c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uname
uname (short for ''unix name'') is a computer program in Unix and Unix-like computer operating systems that prints the name, version and other details about the current machine and the operating system running on it. History The uname system call and command appeared for the first time in PWB/UNIX. Both are specified by POSIX. The GNU version of uname is included in the "sh-utils" or "coreutils" packages. uname itself is not available as a standalone program. The version of uname bundled in GNU coreutils was written by David MacKenzie. The command is available as a separate package for Microsoft Windows as part of the GnuWin32 project and the UnxUtils collection of Native (computing), native Windows API, Win32 porting, ports of common GNU Unix-like utilities. Related and similar commands * Some Unix variants, such as AT&T Corporation, AT&T UNIX System V Release 3.0, include the related setname program, used to change the values that uname reports. * The ver (command), ver comman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SVGALib
SVGAlib was an open-source low-level graphics library which ran on Linux and FreeBSD and allowed programs to change video mode and display full-screen graphics, without the use of a windowing system In computing, a windowing system (or window system) is software that manages separately different parts of display screens. It is a type of graphical user interface (GUI) which implements the WIMP (windows, icons, menus, pointer) paradigm for .... Some popular games like '' Quake'' and '' Doom'' have been ported to use SVGAlib. History The first version of SVGALib was based on version 1.2 of another library, VGALib. SVGALib was popular in the mid-1990s. Toward 2000, many applications that used it migrated to X11 and SDL, which could (until SDL 2.0) make use of SVGAlib as a video driver. References External links SVGAlib*Development versions(link on the site itself is broken) Articles with example C code Free computer libraries Graphics libraries {{Free-softwar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kernel Panic
A kernel panic (sometimes abbreviated as KP) is a safety measure taken by an operating system's kernel upon detecting an internal fatal error in which either it is unable to safely recover or continuing to run the system would have a higher risk of major data loss. The term is largely specific to Unix and Unix-like systems. The equivalent on Microsoft Windows operating systems is a stop error, often called a "blue screen of death". The kernel routines that handle panics, known as panic() in AT&T-derived and BSD Unix source code, are generally designed to output an error message to the console, dump an image of kernel memory to disk for post-mortem debugging, and then either wait for the system to be manually rebooted, or initiate an automatic reboot. The information provided is of a highly technical nature and aims to assist a system administrator or software developer in diagnosing the problem. Kernel panics can also be caused by errors originating outside kernel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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